history Flashcards
(151 cards)
1
Q
what do the detaile
A
Detailed information from papyrus records
Disease caused by god/spirit/supernaturalforce
Shaman-Physicians investigated specific causeof disease and adopted magic rituals,talismans and medicines as treatments
Specialist physicians eg eyes, stomach/bowels,internal fluids, “Shepherd of the Royal Anus”
2
Q
what was the early understanding of human physiology? (Ebers Papyrus)
A
Body served by system of 46 tubes (channels)with heart at centre
Didn’t appreciate functional differencesbetween blood vessels, intestines, airways etc.
Disease resulted as consequence of channel being blocked by the Wehedu (evil spirit)
Physicians would seek practical solutions (cures)to unblock the channels rather than using onlyspiritual approaches
3
Q
how did egyptians learn about anatomy?
A
Egyptians believed in an afterlife -preservation of body after death
Later embalming (Pharaohs and other important/wealthy people)
Organs removed and preserved in jars – kept with mummified body
Mummification -knowledge of internal body structures
4
Q
what were the common diseases in ancient egypt?
A
- Schistosomiasis
- Malaria
- Trachoma (eye disease)
- Small pox
- Measles
- Tuberculosis
- Cholera
- Silicosis of the lungs pneumonia
5
Q
what did ancient greece believe about medicine?
A
- Asclepius : God of healing
- Greek doctors providing rational theory of disease and search for curesIf body had correct balance of hot & cold,wet & dry then you would have health
- Upsetting balance – illne
6
Q
who was the father of western medicine?
A
Hippocrates: “Father of Western medicine” ~460 – 377 BC
7
Q
what did people believe about medicine during the hippocrates period?
A
Healing power of nature
Body rebalance four humours and heal itself (physis)
Therapeutic approach aimed at easing natural processImportance of rest and immobilisation
Emphasis on cleanliness
Drugs/specialised treatments used sparingly
Major advances in prognosis of disease progression based on data collected in detailed case histories
8
Q
what are the four humours?
A
Four humours: blood, black bile, yellow bile, phlegm
In health, four humours in balance (pepsis)
In disease, humours out of balance (dyscrasia)
Therapy = restoration of balance eg Citrus –> phlegm
9
Q
what did fever represent during the aristotle period?
A
Fever = too much blood
this would be treated by cutting the patient to reduce blood
10
Q
Crisis meaning? (aristotle period)
A
Crisis = point in progression of disease where illness
leads to death(alternatively patient might recover
Crises occurred on critical days (fixed time after onset of illness)
11
Q
what did the romans discover in terms of microbiology?
A
- First suggestion of existence of micro-organismsand their association with disease
- Advised avoidance of swamps and marshland
– “breed minute creatures which cannot be seen by the eyes, but which float in the air and enter the body through the mouth and nose and what cause serious diseases.”
12
Q
what did the romans discover about human anatomy?
A
Described properties of muscular tissue and function of principal muscles
Importance of nerves for motion and sensation –sectioning nerve led to paralysis & loss of feeling to body part it served
Nerves communicated information from brain & spinal cord to muscles
Brain & spinal cord were “centre of psychicalforce”
identified distinction between arteries and veins
13
Q
what did the romans forbid?
A
Church forbade dissection of “God fearing bodies”Dissections performed on bodies of criminals/’sinners
14
Q
who was Leonardo Da Vinci?
A
Leonardo Da Vinci was a highly influential in pioneering dissection of human bodies and making careful anatomical diagrams.
15
Q
what did william harvey discover about the circulation of blood?
A
- First accurate description of the movement of blood around the body in a closed circuit Identified:Heart as a co-ordinated pump
- Role of arteries in carrying blood away from the heart role of veins in returning blood to the heart (and the importance of valves)
16
Q
who was JJR Macleod?
A
In the early 1920s Frederick Banting and Charles Best discovered insulin under the directorship of John Macleod at the University of Toronto. With the help of James Collip, insulin was purified,making it available for the successful treatment of diabetes
On 23 January 1923, Banting, Collip and Best were awarded U.S.patents on insulin and the method used to make it. They all sold these patents to the University of Toronto for $1 each.
Banting famously said, “Insulin does not belong to me, it belongs to the world.” He wanted everyone who needed it to have access to it.
17
Q
who was Professor Hans Kosterlitz?
A
One of the University of Aberdeen’s most famous scientists Professor Hans Kosterlitz co-discovered morphine-like chemicals produced in the brain
18
Q
who was John Boyd Orr?
A
1899-1914: Glasgow. Qualifications and degrees in teaching, biology, medicine
1914-1918: Aberdeen and beyond- started at a research institute that would become the Rowettand exposure reality of war in the trenches
1927- proved the value of milk being supplied to school children, which led to free school milk provision in the UK.
1936- “Food, Health and Income” showed that at least one third of the UK population were so poor that they could not afford to buy sufficient food to provide a healthy diet and revealed that there was a link between low-income, malnutrition and under-achievement in schools
19
Q
Who was THE MRI first tested on?
A
In 1980, a man with terminal cancer fromFraserburgh in Aberdeenshire took the bold step of consenting to be the first ever scanned by MRI.
The images showed up clear differences in his liver and spleen and also identified a secondary tumour in his spine which had not previously been known.
It was the breakthrough that Mallard and his team had dedicated more than 20 years to bringing to fruition
20
Q
how can climate change effect pregnancy?
A
We all know that the climate is warming, and that this is changing our weather and increasing the frequency of heat waves, hurricanes,flooding, and drought. Two additional risk factors to the health effects of extreme heat are pregnancy and working outdoors – something millions of women across the tropics, who perform formal and informal labour, experience
21
Q
who was Professor John Mallard?
A
Prof John Mallard : the University’s first Chair of Medical Physics Magnetic Resonance Imaging
22
Q
how do pharmaceuticals impact the enviorment?
A
Wasted or unused medicine is a serious and growing problem within the NHS that you can help tackle.It is estimated that as much as £300 million is wasted every year on unused or partially used medication which cannot be recycled or re-used
23
Q
A
24
Q
how should inhalers be disposed of?
A
All used inhalers should be returned to a pharmacy to be disposed of safely. They can be disposed of by the pharmacist with other drugs waste, this is then thermally treated to destroy the greenhouse gases.This environmentally safe disposal route is available at all pharmacies and is paid for by NHS
25
26
why should inhalers not be thrown into the trash?
There are two main types of inhaler, pressurised canisters, known as Metered Dose Inhalers or pMDI, and powder inhalers, known as Dry Powder Inhalers or DPI.
The propellants used in pressurised canister inhalers are powerful greenhouse gases. Even after the inhaler is spent significant amounts of these environmentally damaging gases remain in the canister
While these gases can be extracted cleaned and reused in industrial equipment, such as air conditioning systems, they are being phased out of use in most applications because of their environmental impacts.
The only environmentally safe way to dispose of them is through thermal treatment, such as incineration. Steel and aluminium may be recovered and recycled at some incinerators.
27
what were the major factors in renaissance medicine?
* Reformation of the Roman Catholic Church
- Galen’s theory of the four humors was disproved
- The church controlled most of the teaching within the universities
* The invention of the printing press
-Allowed news and information to spread quickly and not be held within the monasteries in which they were written
* The invention of the microscope and other instruments
- Instrument quality is intrinsically linked with science* The discovery of new lands allowed pharmacists to make new medicines
- Christopher Columbus
28
what did galen do?
* Claudius Galen (AD 129 – about AD 210)* He used monkeys to study human anatomy
* Some of his ideas were right:* Nerves control muscles* Venous and arterial blood are different
* He could surgically remove cataracts!* Some were wrong:*
- He continues Hippocrates’ bodily humors theory
- Humor imbalances corresponded to different human temperaments
- Venous blood is pumped by the liver
- Arterial blood originated in the heart
- Blood was “consumed” by the organs
29
what was the reformation?
* Began in Europe in 1517 with the aim of reforming the practices of the Roman Catholic Church
* Martin Luther was a German priest whostarted the reformation
- This was largely due to him going against the church selling indulgences to raise money
- He posted theses (which were printed),sparking the protestant reformation
30
how did the reformation impact medical science?
* Destroyed the ideas of Galen as the church no longer had control over much of the learning:
- Mainly through the printing press andthe speed at which teachings could be distributed
- The church could do little to stop the spread of knowledge in light of this invention
31
why was the invention of the printing press so vital to society?
* Allowed discoveries to be communicated quickly
* It also allowed the printing of detailed anatomical drawings far more quickly than hand-copying as had been previously carried out
* De humani corporis fabrica by AndreasVesalius – published in 1543e
32
who was Andreas Vesalius?
* Flemish anatomist Vesalius revolutionized anatomical misconceptions by Galen.
* He utilized dissections as an independent tool.
* Before Vesalius, teachings relied on classic texts like Galen, alongside animal dissections by barbersurgeons.
* Vesalius meticulously documented his work through highly detailed drawings.
* In 1539, a judge approved the use of executed criminals for dissection after discovering Vesalius' work.
* Prior to this approval, Vesalius discreetly used executed prisoners for his dissections.
* The permission significantly hastened Vesalius' discoveries, leading to the publication of his renowned work, De Corporis Fabrica, in 1543.
33
what are barber-surgeons?
* Very common medical practitioners in medieval Europe
* Usually worked on wounded soldiers
* They would also conduct tooth extractions,bloodletting and enemas (!?!)
* Poles were used as hand grips so that veins would show to allow for easier bloodletting either through leeches or razor blades
* Washed bandages from this practice would be hung in a pole to dry outside and the story goes that they would twist around the pole, which was painted red to hide the blood
34
what is altered self control associated with?
Studies in twins suggest changes in underlying fronto-striatal structural changes are associated with altered self-control
35
what is the homeostatic control of feeding?
homeostatic control of feeding is concerned primarily with regulation of energy balance. Hunger as a feeling stems from the hypothalamus, and is influenced by peptides and neuropeptides such as insulin, leptin, grehlin, and also by blood glucose level.
36
what is hedonistic feeding stimulated by?
VTA: stimulated by sensory input
37
what does the Nucleus accumbens control?
reinforces reward behaviour
38
what does the prefrontal cortex control?
thoughts and actions
39
what are the three discaplines is pharmacology a combination of?
pharmacology combines chemistry, pathology and physiology
40
what was opioid pharmacology focused on during the end of the 1800s?
Chemistry- the structure of the main active analgesic in opium (morphine)
- struggle to control its effects
Physiology - not sure how morphine has its effects
- not sure how pain is communicated
- these are critical to understanding the true mode of action of these opioid analgesics
Pathology
- understand the problem of pain and the need for its relief
- pain results from a wide range of diseases/injuries- most types of pain relieved by opium
41
Describe Descartes pain pathway?
1. Particles of heat (A), activate a spot onthe skin surface (B).
2. Activation of B pulls thread connected to a valve in the brain (de).
3. Allows “animal spirits” stored in cavity Fto flow out.
4. These spirits are responsible for:- the pain itself- withdrawal of the leg from the heat- turning the head toward the origin of the pain
42
what is the modern pain pathway?
pain is sensed and the individual responds
- connects to the thalamus, relays pain message to different parts of the brain
sensory nerve enters spinal cord and connects to another nerve fibre
nerve fibre ascends spinal cord into the brain
43
how do opioids regulate the pain pathway?
Solomon Snyder discovered the opioid receptor in 1972
- these receptors present in the brain and spinal cord
- specifically bind to morphine and other similar opioids e.g. codeine and heroin
- several different receptor sub-types discovered this
explains spectrum of opioid actions (analgesia, sedation, anti-diarrhoea)
- binding of opioid to receptor inhibits nerve fibre and prevents it firing opioid
44
how does morphine work?
binds opioid receptors inhibits pain fibres in brain & spinal cord hence effectiveness
45
how did the discovery of morphine and the pain pathway influence pharmacology
- synthetic chemistry permitted drugs to be developed based on morphine but with subtle differences
- these altered the activity and properties of the new drug
- many drugs like this in use today
- 1st isolation of an active ingredient for any drug
- provided first proof that pure chemicals in plants and natural products were responsible for biological responses
46
what are some examples of synthetic opioid drugs?
buprenorphine, methadone, pethidine and fentanyl
47
what is the first mechanism in pain response?
when we are in pain, a fibre inhibits the pain signal in the spinal cord - less pain signals to go to the brain and we suffer less
rubbing activates another type of sensory receptor connected to a fibre that enters the spinal cord
48
what is the 2nd mechanism in pain response?
Kosterlitz and Hughes discovered the descending pain -inhibitory pathway
these nerve fibres release our own “home-made” (endogenous) opioids called enkephalins/endorphins
49
why was Hans Kosterlitz interested in pain mechanisms?
intrigued by reports of wounded soldiers not feeling pain during battle
investigated whether our brains can produce their own natural analgesics
50
describe the pain inhibitory pathway?
inhibits pain transmission in spinal cord
- releases enkephalin
- binds opioid receptors
- inhibits pain fibre firing
this pathway is stimulated by:
- stress (adrenaline)
- emotions
- opioid drugs
this pathway controls pain and suffering
- allows us to escape stress/dange
51
what does the pain pathway connect?
pain receptors through the spinal cord to the brain
52
what can the pain pathway be modulated by?
sensory nerve activation
endogenous opioids(descending pain-inhibitory pathway
53
what are other methods of analgesia?
local anaesthetics + anti-inflammatory drugs (ibuprofen, paracetamol, aspirin)
TENS (transcutaneous electrical nerve stimulation)
- electrical impulses applied across the skin of the lower back activates inhibitory sensory fibres (blue)
general anaesthetics
- induces loss of consciousness
- no perception/memory of pain
acupuncture - stimulates the release of enkephalins
54
how did we assess injuries before x-rays?
If you broke a bone or damaged yourself the only way of assessing you would be through touch
- Difficult if there’s lots of swelling and pain.
If you managed to lodge something inside you (e.g. swallowed something), the only way of finding it would be through touch, or possibly using a stethoscope to identify changes in the way sound travels through your body
55
how are photographs and x-rays linked?
* The technological advances of Victorian times lead to a massive increase in photography and photographic equipment
* Photographs flourished as a means of the middle classes having family portraits
* Without this advance in technology the x-ray would not have been possible
56
what did sir william crookes do?
* Prior to x-rays, Sir William Crookes was investigating cathode rays using vacuum tubes (later known as Crooke’s tubes)
* A high voltage in the tubes causes electrons to pass from one end to the other and generate the image of the cross on the other end of the tube
* The glow created by the electrons is them releasing energy as they hit the end of the tube
* The image of the cross occurs because the metal cross blocks the electrons
57
who discovered x-rays and how?
* Wilhelm Röntgen was a not very academic individual who ended up discovering x-rays by accident
* He went from high school drop out to a Nobel laureate
* He was working on cathode rays using a similar device to the Crooke’s tube because he thought the cathode rays penetrated the glass of the tube
* They actually barely penetrate the glass
* He then set about testing what the mysterious rays could pass through
* As he held the materials in front of the rays he could see the shadow they projected on the painted screen
* During this process he spotted ghostly shadows of his own bones
* The next obvious thing was to expose his wife to the rays!
* this was the first x-ray image
58
what were x-rays originally used for?
* Initially the medical world was suspicious of the discovery, but x-ray practices were beginning tobe run from peoples homes
* It was used a lot in the location of foreign bodies and even used to treat skin disorders or make women look beautiful
* These latter uses caused some pretty horrible side effects though
59
how is an x-ray constructedand how do they work?
* X-ray tubes were developed from Röntgen’s simpletube design
* High-energy electrons pass from the cathode, through the tube, and hit the metal target on the anode,releasing high energy radiation (x-rays)
* These new designs allowed x-rays to be more focused and directed
* This therefore opened the doors for more uses of thex-ray in the medical science
60
how do x-rays work?
* The x-rays are high energy light waves
* Dense objects can absorb the x-ray photons
- e.g. Bones, which leave a shadow on the photographic film
* Not so dense objects allow x-ray photons to passthrough unhindered
-e.g. Soft tissue, which allow the x-rays to leave an image on the photographic film
* This process is akin to the cross generated in Crooke’s cathode ray tube
* Your bones create a shadow of themselves on the photographic film
61
how do we detect x-rays?
* Photographic plate
-Needs wet lab handling techniques as in processing photography films
* Photostimulable phosphors
- Used in modern hospitals today by converting the image of the phosphorous glow to a digital image to create the x-ray image
* Semiconductor detectors
- Work in a similar way to the TFT screens that are in computer monitors,but to record the image, not produce an image like a monitor does
62
what is the definition of radiology?
The specialised use of x-rays for diagnostic imaging
63
what can be used instead of x-rays? (3D/2D imaging)
While the x-ray is still very useful, for complex diseases or conditions a 2-D image is not good enough to see the problem clearly
CAT (computer aided tomography) or CT (computertomographie) scans use computers to aid in the detailed reconstruction of a 3-D image of the subject
64
what other uses do x-rays have other than imaging?
* X-ray microscopes
Can detect very small objects
Single cells can be analysed in this way
* Röntgenstereophotogrammetry
Analyses the precise position of markers within the body
Useful to detect changes in joint replacements orwhen bones are extended
* X-ray crystallography
Allows the precise locations of individual atoms to be identified from crystals
Many biological molecules can be detected in this way
65
how does an x-ray crystallorgraphy work?
* Must have a crystal to analyse the structure of a molecule
* Very pure sample with an ordered structure
* The sample is rotated in the x-ray beam and the diffraction pattern measured
* Very powerful computers can piece together this information to form an electron density map (a“shadow” of the crystal on the detector)
* Computers again are used to then make larger multi-atom models of the biological molecule of interest
66
what are some imaging techniques?
* X-ray
* fMRI
* Ultrasound
* Bioluminescence
* Angiography
67
what is an MRI?
* Magnetic Resonance Imaging
* Nuclear Magnetic Resonance(NMR) Imaging
* Much better soft tissue visualisation compared to x-ray orCT scan
68
how do MRIs work?
* The body is composed of 55-65% H2O and it is the proton nuclei that are detected in MRI
* The magnets align the nuclei and put them in an “excited”state
* The MRI scanner then passes radio frequency waves through you specific to hydrogen which cause the aligned nuclei to shift by 90° (resonance)
* When the radio frequency is removed the nuclei return back to their aligned state but in doing so release a small amount of energy, which is recorded
* The computer collates this information to “draw” an image of the body as the protons return to their aligned state
* Because it is viewing individual atoms, it can produce very thin slices and therefore much more detail than a CT scan
* Different tissues respond differently to this change in magnetic field, so you can get a highly detailed picture of the body
69
how has the MRI revolutionised medicine and why is this contraverisal?
* In 2003 Paul Lauterbur and Sir Peter Mansfield were awarded the Nobel Prize In Physiology or Medicine
* This was disputed by several scientists
* Raymond Damadian claimed he invented the MRI machine first
* Vladislav Ivanov claimed he had invented a 1-D MRI machine
* Herman Carr had also invented a machine capable of magnetic imaging earlier than Lauterbur and Mansfield
70
how can scientists visualise the living body?
* Many techniques exist to view living organs in real-time rather than looking at static images
- The main advantage of these is to show the body over time asit changes
- After all, the body is not a static object
* Ultrasound
- Identifies structures within the body using sound waves* Bioluminescent imaging
- Uses luminescent markers to identify structures within the body
- Predominantly research based to date
* Angiography
- Visualises blood vessels in living tissue (e.g. the heart)
* Functional MRI (fMRI)
- Identifies regions of tissue that are biologically active
71
what is the relationship between the MRI and Aberdeen?
* The world’s first full-body MRI scanner, known as Mark-I
* Prof James Hutchison developed this full-body scanner throughout the 1970s
* 1st patient was an elderly gentleman from Fraserburgh
72
when was the first successful fMRI experiment?
* First successful experiments happened in 1991 – so it’s not very old
73
how does an fMRI work?
* Identifies active neuronal activity
* Scanner can identify cell activity through O2 usage
* Active cells = more O2 consumption
* Can plot this information on top of an MRI scan
74
give an account of the scottish history of ultrasounds
* Prof Ian Donald used ultrasound for the first diagnostic applications as an obstetrician at Glasgow Maternity Hospital
* First he used cadaveric anatomical specimens to test his ideas of using ultrasound to identify structures within the bodies
* In Glasgow, Donald along with Dr James Willocks refined the method so it could be used to define the growth developing foetus
* This improved the outcome of pregnancies dramatically as doctors now had the ability to identify complications
75
how do ultrasounds work?
* Ultrasonic (we can’t hear them) sound waves pass through soft tissue easily and are reflected to differing degrees by internal structures
76
what are the developments that have been made in ultrasounds lead to?
* 3-D ultrasound
- Provides much more detail than 2-D*
- Is not any better at identifying problems
* Echocardiography
- Uses Doppler effect to monitor movement
- Can be 2-D or 3-D
- Allows doctors to identify problems with minimal invasive techniques
77
what does the doppler effect state?
Doppler Effect refers to the change in wave frequency during the relative motion between a wave source and its observer
78
when was pharmacology developed as a precise science?
developed as a precise science in mid-1800s
79
how can the doppler effect be used in ultrasound?
* This principle is used in Doppler ultrasound to identify moving parts (e.g. Blood flow,or muscle contraction)
* So, in Doppler ultrasound, if blood is moving away from the sensor the Doppler effect would cause the reflected sound waves to be longer than the original wave
* If blood is moving towards the sensor the Doppler effect would cause the reflected sound waves to be shorter than the original wave
80
where is bioluminescent imaging used?
Mainly used in medical science research rather than clinical use
81
how does bioluminescent imaging work?
* Uses fluorescent proteins to identify structures, usually in animal models
* Transgenic mice can be generated that have genes encoding fluorescent proteins that are only switched on in specific places
* Very sensitive cameras can then detect the light generated by the proteins
-Green fluorescent protein
-Luciferase
82
what is Luciferase?
* An enzyme found in many species of insect that emit light for communication purposes
* The gene encoding this protein has been isolated and can be used to artificially produce lots of this enzyme
* When the enzyme is mixed with a specific substrate, the reaction emits a very bright light
* This reaction occurs in the abdomen of the firefly, but can also be reproduced in the lab
* The gene can also be inserted into animal DNA to produce transgenic animals that express the firefly protein in specific places
83
how is luciferase used in imaging?
* If the gene is only switched on in cancerous cells in mouse models then only the cancer cells will light up
* Can also be used for other cell types
* Very sensitive cameras can detect this light through the skin* This method of imaging is highly quantitative because the amount of light is directly proportional to the amount of gene expression occurring within the animal tissue
84
what is an angiography?
* To visualise blood vessels in real time in living tissue
* It uses x-ray technology, but usually with live image capture
* Can be used on virtually any region of the body that has blood vessels
* Commonly used for blood vessels in the
- Brain
- Heart
- Kidneys
85
what is a coronary angiography?
* One of the most common angiography procedures
* Allows physicians to visualise the blood vessels of the heart
* Often used for coronary heart disease caused by narrowing of the blood vessels that supply the heart (coronary arteries)
- Occlusions
- Thrombosis
* Usually stents are inserted into the blocked arteries
* Can be used to view the heart muscle contractionsas well
86
how is a coronary angiography performed?
* Catheter (about 2-3 mm wide) is inserted into an artery of either the armor groin
* The blood arteries are injected with a radiocontrast agent (usually called an X-ray dye) to visualise the blood vessels
* X-ray images are recorded to position the end of the catheter at the site required by the surgeon
* the procedure will then take place
- Balloon catheters
- Stents
87
what is the definition of pharmacology？
studying the effects of drugs on the function of living systems
88
what is a drug?
a chemical substance of known structure (other than a nutrient or essential dietary ingredient), which, when administered to a living organism, produces a biological effect
can describe active ingredient in a medicine or a research tool
89
what is a medicine?
chemical preparation administered with the intention of producing a therapeutic effect.
will contain the drug (active ingredient) and also stabilisers,solvents etc that help make the drug more effective/useful
90
why is chemistry, physiology and pathology important in pharmacology today?
* Chemistry
- need to know chemistry of drug and it’s target
- drug activity directly related to it’s structure
* Physiology
- need to know how biological organism works
- need to know what “normal”biological function/activity of the organism is
* Pathology
- need to know how disease/damage affects organism
- an understanding of disease process/cause/progression useful for designing intervention therapy
91
what was the ebers papyrus?
* ancient Egyptian text detailing Egyptian medicine
* one of oldest medical/pharmacological texts- examples of recommended treatments:
- Asthma - herbs heated on a slate so sufferer could inhale
- Constipation - used a prune-based mixture
- Cancer - recommends “do thou nothing there against”
- Death - recommends half an onion and beer froth “a delightful remedy against death”
- Guinea worm (3rd world parasite infecting subcutaneous tissues) – recommends wrapping end of worm around a stick and winding slowly to remove worm (this is the standard practice today)
92
who was Pedanius Dioscorides?
-* Greek physician, pharmacologist and botanist
- surgeon in the army of Emperor Nero
* extensive travels throughout ancient world- wrote 5 volume encyclopedia - De Materia Medica
- details medicines used by Greeks, Romans and other civilisations
- also an important document for identifying/naming plants
- extensively used/reproduced for around 1000 years!!!
- updated as it was transcribed through the civilisations
- contains information from a broad base of cultures
93
what early therapies persisted into the 18th century?
* leeches - based on anecdotal evidence,spiritual beliefs and availability
* worms - no understanding of how remedies (drugs) worked
* dung - not patient friendly
* moss - flimsy, “suck-it and see” science
* decaying fish - lacked control and credibility
94
who were the fathers of pharmacology?
* Rudolf Buccheim (1st Professor of Pharmacology in 1847)
- emphasised the importance of defining drug mode of action- this would develop understanding of drugs, doses etc
- developed experimental pharmacology to investigate
* Oswald Schmiedeberg (Buccheim’s student)
- succeeded Buccheim in 1869
- defined what is now modern pharmacology
95
why do humans feel pain?
- warns us of actual or potential tissue damage
- encourages us to withdraw limb/tissue from danger
- promotes us to protect damaged tissue to aid healing
- ensures we remember the incident and learn from the experience
96
what were the methods of pain relief in the past?
* Some methods to relieve pain stretching from Ancient Rome 1800s include:
- spells and incantations
- diet
- exercise of the painful region
- consumption of potions/formulations
- removal of painful limb/tissue/organ
- “bleeding” of the painful region or use of leeches
- “purging” the body (laxatives and emetics)
- burning/scalding
97
what is the humoral balance?
* ancient view of the body existing as a delicate balance of 4 fluid components: blood, phlegm (water), yellow bile (liver), black bile (gall bladder)
* imbalance of these 4 fluids lead to disease, distress and pain
- many pain relieving methods were designed to restore this balance
98
when and where was opium discoveredand what was it used for?
* traced back to 4000 BC in Middle East
- gummy substance extracted from opium poppy plant
- opium poppy termed Hul Gil – “joy plant”
* spread through Egypt to Greece and through Europe- described in The Ebers Papyrus, De Materia Medica and other ancient texts
* ancient use described in such texts includes:
- pain relief, sponging surgical wounds
- sleep induction, euthanasia
- soothing a crying child, calming “disturbed” individuals
99
what did hippocrates use opioids for?
used opium to treat headaches, coughs, asthma and melancholy
100
when did opioids reach the UK?
reached UK in late 17th century
- still a non-refined extract from the poppy plant, dissolved in alcohol
- “tincture of opium”
- so dose and effectiveness not controlled or understood
101
what is the most abundant active component of opioid extract?
morphine
102
who invented the hypodermic needle?
alexander wood
102
why was the invention of the hypodermic needle important? (morphine)
before this morphine was taken orally (less potent/addictive)
intravenous administration increased morphine potency leading to increased opioid abuse and addiction emerged as a MAJOR side-effect
during the American civil war, morphine widely used to treat wounded soldiers and gave rise to hundreds of thousands of opioid-addicted soldiers
- “soldiers disease"
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why are ampoules used?
Ampoules such as this still in use today. 2 primary reasons:
1. morphine is an effective pain killer
2. intravenous administration is easy and effects are almost instantaneous
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what is the history of Diacetylmorphine (heroin)?
* early “semi-synthetic”
- attempt to alter natural substance to improve properties
* a “non-addictive” substitute for morphine
- cough suppressant & analgesic
- oral administration -> converted to morphine
- intravenous administration -> more potent/addictive
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what is the function of a light/optical microscope?
uses visible light and lenses to magnify images
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what is the difference between an inverted and upright microscope
Upright microscope has light source below stage
Inverted microscope has light source above stage
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how do light microscopes work?
Light Source: This provides the necessary illumination to view the specimen. In many microscopes, it's a built-in lamp.
Specimen: The object or sample you are examining under the microscope. It's typically a thin slice or preparation of some material, often biological, placed on a slide.
Condenser Lens: This component is designed to focus the light from the light source onto the specimen, ensuring even illumination.
Objective Lens: This is the primary magnifying lens. Microscopes often have multiple objective lenses on a rotating turret, allowing users to choose different magnifications. e.g., 10X 40X 100X
Eyepiece (Ocular): Positioned where you place your eye, the eyepiece provides additional magnification to the image produced by the objective lens.
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what are the cons of a brightfield microscopy?
2-dimensional
Lacks detail
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what is magnification?
Magnification is the enlargement of an object compared to its actual size. It's represented by a ratio, such as 10X, indicating it's magnified 10 times its original size. Magnification is determined by multiplying the magnifications of the two lenses used
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what are the power levels of magnification?
Low-mid power magnification
- useful for scanning broad aspects of the specimen
Higher power magnification
- useful for increased detail, but lose appreciation of some areas of the specimen
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what does resolution mean in terms of microscopes?
Resolution in microscopy refers to the clarity or "sharpness" of an image, specifically the capability to distinguish between two closely situated points. It's influenced by the wavelength of the light source. As a general rule, based on Abbe's Law, objects smaller than half the wavelength of the light can't be distinguished. For a light microscope using white light with a wavelength of ~0.55 μm, objects below 0.275 μm will merge and appear indistinguishable, causing the image to look blurry.
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what is the fixation procedure? (microscopy)
fixation is the procedure used to prepare samples for the microscope as samples are usually from sections or slices of tissue which can cause issues as cells are quite transparent and therefore require preparation for proper study
* immerse cells in a fixative (preservative) solution e.g. formaldehyde
function
* kills cells, cross-links proteins with covalent bonds
- stabilises protein, prevents degradation
- creates a biological “snapshot” of the tissues biology
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what is another procedure used to prepare cells for microscopy (not fixation)
“snap-freeze” tissue in liquid nitrogen (-196 oC)
Produces a solid, section, which is preserved provided it remains frozen
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what are the challenges posed by trying to use microscopes on a cell that hasn't been prepared beforehand?
1. tissue may change biologically as it is prepared
2. tissue is flimsy, so slicing it not possible
3. require thin sections to make individual cells visible
4. thin sections are likely to be quite transparent
this can be fixed by fixing, embedding, sectioning and staining the samples beforehand
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what is the embedding procedure (microscopy)
the procedure involves fixed tissues being embedded in wax/resin which will harden
in liquid form, the wax or resin penetrates the tissue
upon cooling it will harden to form a solid block of tissue
-> tissue no longer flimsy
->now a solid block, making sections or slices easier to cut
embedding cannot be used on frozen tissue as they are already solid
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what is the sectioning procedure (microscopy)
- tissue blocks sectioned or sliced using a microtome
- microtome = precision instrument with a sharp blade (think meat slicer)
- sections collected on a glass slide
this is useful as slicing tissue blocks into thin sections allows the sections to be thin enough to permit visualisation of individual cells
frozen tissues are sectioned on a special cold microtome (cyrostat)
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what is the staining procedure in microscopy?
this involves tissue sections being stained with organic dyes
this is useful as:
- dyes specifically stain subcellular compartments/structures/molecules
- identifies structures in cell
- provides contrast in the previously transparent section of tissue
- choice of stain depends on tissue and what you want to see
- many dyes available
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what is the visable spectrum?
wavelengths (in nm) & their corresponding colours across the spectrum
special “filters” exist that only allow light of a set colour/wavelength
all of these are detectable by the human eye
this means we can isolate single colours/wavelengths of light
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what does fluorescent molecules do in microscopy?
Fluorescence increases microscopic sensitivity
florescent molecules absorb light of a given wavelength (excitation wavelength)
and emit light at a different, longer wavelength (emission wavelength)
light of a given wavelength -> fluorescent molecule -> emits green light
this is the basis of fluorescence microscopy
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what is fluorescence?
Fluorescence = emission of light in response to stimulation by electromagnetic radiation
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how does a fluorescence microscope work?
Specimen (1): Contains fluorescent molecules; emits green light when excited by blue light.
Blue Filter (2): Allows only blue light (~480 nm) to pass.
Mirror (3): Reflects light below 510 nm (e.g., blue) but allows light above 510 nm (e.g., green) to pass.
Green Filter (4): Permits only green fluorescent light.
Eyepiece (5): Displays green fluorescing molecules against a dark background
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what are the advantages of fluorescent microscopy over organic staining?
- can detect specific molecules inside or outside cells
- dark background increases contrast and sensitivity so even a small number of fluorescing molecules will be visible
- endless flexibility in the types of experiments you can do
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What is the relationship between the emission wavelength and the excitation wavelength in fluorescence?
emission wavelength always longer than excitation wavelengths
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what is green fluorescent protein?
* found in a specific breed of jellyfish
* GFP glows intensely green when excited with blue light
- the main fluorescent protein
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In fluorescent microscopy, why are different sets of filters used?
Different sets of filters are used to match the specific excitation and emission wavelengths of the fluorescent molecules being observed.
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how was Green Fluorescent Protein found?
* first isolated in the 1970s
* developed and improved into the 1990s
* simple changes to its structure changes the profile of its excitation and emission colours giving rise to:
- cyan fluorescent protein (CFP)
- yellow fluorescent protein (YFP)
- red fluorescent protein (RFP)
these are “tweaked” forms of GFP, with different wavelength characteristics
* cloning technologies, molecular biology and transgenic animal studies mean it is widely used in many different ways
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who were the 3 GFP scientists awarded a nobel prize (chemistry) in 2008?
Martin Chalfie
Osuma Shimomura
Roger Tsien
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how can GFP be used?
* DNA encoding GFP (the GFP gene) can be inserted into living cells
- cells can then be visualised while alive using the fluorescence microscope
* DNA encoding GFP (the GFP gene) can be inserted into living animals
- used to examine how genes are expressed in whole, living animals
- also used to track genes important in development and disease
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how does live cell imaging work?
allows changes in cell behaviour to be monitored in real-time
requires microscope to be housed in an incubator unit
- maintains temperature at 37 OC
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How can we achieve higher resolution in microscopy than what light microscopy allows?
By using an illumination source with a shorter wavelength, such as a beam of electrons in electron microscopy.
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Why do electron beams offer higher resolution?
Electrons, at high velocities, have very short wavelengths (around 0.004 nm) which allows for extremely high-resolution imaging.
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While the theoretical resolution limit of electron microscopy is as low as 0.002 nm, what is the more realistic resolution due to practical limitations?
The more realistic resolution is around 0.1 nm.
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How does the resolution of electron microscopy compare to light microscopy?
Electron microscopy offers up to 1000 times better resolution than light microscopy
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how does an electron beam work in a transmission electron microscope?
* TEM has the same principles, different radiation as Light microscopy
* travels in vacuum
* focused by magnetic coils (in place of lenses from light microscope)
* passes through specially-prepared specimen
absorbed by more electron-dense areas of specimen
* these appear lighter on image
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what is a scanning electron microscope?
* variation of transmission electron microscope
* capable of producing 3D pictures – lower resolution/magnification
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how does the electron beam work in a scanning electron microscope?
SEM works in the same way as TEM, but doesn’t measure electrons absorbed by specimen
instead measures electrons that bounce off the specimen or that are scattered by it
produces 3D image of surface of specimen
can only examine surface features though
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what is the main flaw of electron microscopes that makes them less-accessible?
they are big and expensive, but hugely important for modern medical science
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who designed and worked on electron microscopes?
Designed by Ernst Ruska (1930s)
Nobel Prize for Physics (1986)
Shared prize with 2 other microscopy pioneers
Initial work by Max Knoll (1930s)
Improved, developed and commercialised by Charles Oatley (1960s)
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What early method did Chinese physicians use in the 1st Century AD to prevent smallpox, and what were the outcomes?
- Chinese physicians noticed that survivors of smallpox did not contract the disease again.
- They experimented with inoculation by having "volunteers" sniff powder from dried smallpox scabs.
- This often resulted in the subjects contracting a mild form of smallpox 8-9 days later, from which they usually recovered.
- However, the practice was not without risk: some subjects suffered from severe smallpox, and there were instances of new outbreaks being started.
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what was Jenners experiment?
* Dr Edward Jenner inoculated 8-year-old James Phipps with matter from a cow pox sore on the hand of Sarah Nelmes, a local milkmaid.
* Phipps reacted to the cowpox matter and felt unwell for several days but made a full recovery. Two months later, in July 1796, Jenner took matter from a human smallpox sore and inoculated Phipps with it to test his resistance.
* Phipps remained in perfect health, the first person to be vaccinated against smallpox
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What was variolation?
Variolation = inoculation with smallpox
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who introduced variolation to britain?
- It was popularized in Britain in the early 18th century by Lady Mary Wortley Montagu.
- Lady Montagu contracted smallpox while in Turkey at age 26, which led to severe facial scarring. Her brother had died from the disease two years earlier.
- She observed elderly Turkish women regularly performing the procedure of engrafting smallpox material to others, which inspired her.
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what were the challenges faced when introducing variolation into britain?
- Despite major opposition, Lady Montagu campaigned for variolation to be introduced in Britain, arguing for its effectiveness based on her observations.
- Her efforts were met with skepticism and bias due to the treatment being foreign, her being a woman, and the procedure often associated with rural and nomadic populations.
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Who created the world's first vaccine and what was the principle behind it?
- Edward Jenner, an English physician, created the world's first vaccine in May 1796.
- Jenner used a principle similar to variolation but instead used cowpox, a less dangerous virus, to confer immunity against smallpox.
- This innovation was influenced by local rural beliefs and practices that suggested those who had contracted cowpox were protected from smallpox.
- Jenner's work laid the foundation for modern vaccines and immunology.
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why were Edward Jenner's findings denied by the church?
* Jenner tried to publish his work through the Royal Society but hispaper was rejected?
* Jenner published privately (1798) –coined term vaccination (vacca = cowin Latin)
* Major criticism from church –vaccination against God’s will
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who were benjamin jesty and peter plett?
Edward Jennings wasnt actually the first to do what he did:
* Benjamin Jesty (farmer from Dorset) used darning needle to transfer cowpox to his two sons and wife during 1774 smallpox epidemic in Yetminster (22 years before Jenner)
* Peter Plett (teacher from Kiel, Schleswig-Holstein (Germany)) vaccinated three children with cowpox in 1791 – protected against smallpox
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When did the WHO launch its smallpox vaccination program and what were its outcomes?
The WHO launched a vaccination program to eradicate smallpox in 1967.
- The last case of naturally transmitted smallpox was reported in Africa in 1977.
- In 1980, the WHO officially declared the end of smallpox as a naturally occurring disease.
- smallpox was responsible for an estimated 500 million deaths worldwide during the 19th century.
- The only remaining stocks of the smallpox virus are held in the USA and Russia for research purposes.
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who were the main people involved in renaissance medicine?
* Several key people involved
- Andreas Vesalius
- William Harvey
- Ambroise Paré
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